Black and Blue spots on my Phone Display

@moin27555 without actually seeing it and only going by your brief description, this sounds like a broken display. To verify that this is a bad screen, you want to go ahead and post some pictures of what it shows, with your Question. That way we can confirm this.

SInce iFixit does not yet have a guide for that, use the one from here Replacement displays are readily available at plenty of online stores.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Adding images to an existing question

Repair is War on Entropy!